Problem: Divide.
There are many ways to solve this problem. Let's see two ways we could divide. Place value strategy We can think in terms of tenths: $\begin{aligned} 122 \div 0.1&= 122.0 \div 0.1\\\\ &= 1{,}220\text{ tenths} \div 1\text{ tenth}\\\\ &= 1{,}220 \end{aligned}$ Fraction multiplication strategy Decimals are a kind of fraction, so we can use fraction multiplication. $\begin{aligned} &\phantom{=}122 \div 0.1 \\\\ &= \dfrac{122}{0.1}\\\\ &= \dfrac{122 \times 10}{1\times 10}\\\\ &= \dfrac{1{,}220}{1}\\\\ &= 1{,}220 \end{aligned}$ The answer $1{,}220 = 122 \div 0.1$